JPH0926042A - Motor-driven three-way valve and air conditioner for cooling and heating to use this motor-driven three-way valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of changeover sound and also realize the linear control of refrigerant regulation and in addition to realize space saving. SOLUTION: A valve body 8 ascends due to the rise of a guide pert 16, and a valve part 8a is separated from a first valve seat 6, and a fluid flows from a first passage 2 to a second passage 3. When the guide part 16 is rotated by impressing a power source on a coil 15, the guide part 16 descends, and the first valve seat 6 is gradually closed by means of the valve part 8a. When the guide part 16 is further rotated, although the valve body 8 remains in that state, a check valve 9 furnished slidably to the valve body 8 is pushingly moved downward, so opening control at a second valve seat 7 is conducted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling / heating air conditioner using an electric three-way valve and an electric three-way valve capable of simultaneously cooling and heating a plurality of indoor units.

[0002]

2. Description of the Related Art A conventional multi-room type air conditioner capable of cooling or heating all of a plurality of rooms (indoor units) at the same time, and cooling any one of the plurality of rooms at the same time and heating the remaining rooms. For example, JP-A-3-55475 can be cited. In this apparatus, the outdoor unit and the plurality of indoor units are connected by three unit pipes, which are a high pressure gas pipe, a low pressure gas pipe, and a liquid pipe. A switching valve is provided in each of the high-pressure gas pipe and the low-pressure gas pipe to switch between cooling and heating, and a refrigerant depressurizing mechanism is provided on the indoor unit side. In the air conditioner having such a configuration, there are three unit-to-unit pipes between the outdoor unit and each indoor unit, which makes the piping work troublesome and requires decompression / opening / closing functions on the indoor unit side. There is a problem of losing compatibility with the room air conditioner. Further, since the switching valve is composed of the solenoid valve, there is a problem that switching noise is generated or refrigerant noise is generated from the throttle mechanism or the like.

[0003]

Therefore, it is an air conditioner (refrigerant circuit) shown in FIG. 4 that attempts to improve the technique described in the above publication. In FIG. 4, 51 is an outdoor heat exchanger, 52 is a compressor, and 61a and 61b are indoor heat exchangers. Then, one end of the outdoor heat exchanger 51 is connected to the compressor 52.
Of the indoor units 60a, 60b are branched and connected to the discharge pipe 53 and the suction pipe 54 of the respective units via the switching valves 55a, 55b.
The gas pipes 62a and 62b of the unit pipe to the discharge pipe 53
To the suction pipe 54 and the switching valves 63a, 63b and 64a, 6
They are branched and connected via 4b. Further, throttling mechanisms 56, 65a, 65b are provided on the other end of the outdoor heat exchanger 51 and the liquid pipe of the inter-unit piping. Then, the switching valves 63a, 63b and 64a, 64b, the throttle mechanism 65.
a and 65b are provided on the outdoor unit side. As a result, by moving the decompression / opening / closing mechanism on the indoor side to the outdoor unit, two pipes can be connected as before, and the indoor unit can be interchanged.

FIG. 5 shows a refrigerant circuit which is intended to be improved from FIG. 4, and is an example in which three-way switching valves 71a, 71b, 71c are used in place of the pair of switching valves 55a ... Shown in FIG. These three-way switching valves 71a, 71b, 71c are provided on the outdoor unit side. In this case, two switching valves can be replaced by one three-way switching valve, so the outdoor unit can be made compact and space-saving. However, the conventional switching valve described above, the switching valve shown in FIG.
Since the three-way switching valve shown in (1) was composed of solenoid valves, there was a problem that switching noise was generated during switching and the refrigerant flow rate could not be controlled. Further, the conventional switching valve is also expensive.

The present invention has been made to solve the above-mentioned conventional drawbacks, and an object thereof is to provide an electric three-way valve capable of preventing the generation of switching noise and controlling the flow rate of the refrigerant. An object of the present invention is to provide a cooling / heating air conditioner using this electric three-way valve.

[0006]

Therefore, in the electric three-way valve according to the first aspect of the present invention, the flow passage 5 extending in the axial direction of the main body casing 1 is formed, and one end side of the flow passage 5 is set to the first passage 2. The other end side is connected to the third passage 4 and the middle portion thereof is connected to the second passage 3, and in the flow passage 5, the first valve seat is provided between the first passage 2 and the second passage 3. 6 to the second passage 3
A second valve seat 7 is provided between the second valve seat 7 and the third passage 4, and the second valve seat 7 is provided in the flow path 5 along the axial direction thereof.
A valve body 8a is provided for penetrating through the valve body 8 and extending toward the first valve seat 6 side, and a valve portion 8a for controlling the opening degree by approaching or separating from the first valve seat 6 on the tip side of the valve body 8. Further, a check valve 9 is slidably inserted into the valve body 8 at a position closer to the tip end side than the second valve seat 7, and the check valve is actuated by the fluid pressure acting in the flow path 5. 9 is configured to be pushed to close the second valve seat 7, and an electric drive mechanism 13 for driving the valve body 8 and the check valve 9 is further provided. With the electric drive mechanism 13, The check valve 9 is moved to the second valve seat 7 by the fluid pressure in the flow path 5.
Is closed and the first movement of the valve body 8 caused by the axial movement
In the first state in which the opening degree is controlled in the valve seat 6, the check valve 9 closes the second valve seat 7 by the fluid pressure in the flow path 5, and the valve body 8 closes the first valve seat 6. In the closed second state, the check valve 9 is moved against the fluid pressure in the flow path 5 to control the opening degree of the second valve seat 7, and at the same time, to open the valve body 8
It is characterized in that the first valve seat 6 is closed and the third state is formed.

According to the electric three-way valve of claim 1,
In the first state, since the opening degree control between the valve portion 8a and the first valve seat 6 is performed, it is possible to open and close between the first passage 2 and the second passage 3 and adjust the flow rate. The second valve seat 7 is closed by the check valve 9 due to the pressure in the flow path 5. From this first state, the electric drive mechanism 13 drives the valve element 8 in its axial direction to shift to the second state in which both the first valve seat 6 and the second valve seat 7 are closed. Further, the check valve 9 is driven from the second state to the valve portion 8a side of the valve body 8 to shift to the third state in which the opening degree of the second valve seat 7 is controlled. Further, by driving the valve body 8 and the like in the opposite direction to the above, the second valve seat 7
It is possible to smoothly shift from the opening of only the first valve seat 6 and the second valve seat 7 to the closed state, and further to the first state where only the first valve seat 6 is opened.

In the electric three-way valve according to the second aspect of the invention, the electric drive mechanism 13 has the guide portion 16 which is rotationally driven by the electric current flowing through the coil 15, and the shaft portion 18 which is provided in the main body casing. 1 is configured to be screwed into a screw hole 10 provided in No. 1 to convert the rotation of the guide portion 16 into a linear reciprocating motion, and the valve body 8 slidably penetrates the shaft portion 18. The valve body 8 is introduced into the flow path 5, and the valve body 8 can be interlocked with the guide portion 16, and the guide portion 16 moves the valve body 8 in a direction of closing the first valve seat 6. Thus, after the valve portion 8a of the valve body 8 contacts the first valve seat 6, the guide member 16 is further supported by the guide member 16 so as to be movable in the same direction. By the movement in the same direction, the tip portion of the shaft portion 18 It is characterized in that it is configured to push the check valve 9 in the opening direction.

According to the electric three-way valve described in claim 2,
In the transition from the first state to the third state, or from the third state to the first state, the guide portion 16 is rotated, and the shaft portion 18 of the guide portion 16 and the screw of the main body casing 1 are rotated. Since the guide portion 16 is linearly reciprocated by being screwed into the hole 10, the valve body 8 and the check valve 9 can be smoothly moved in the axial direction, and therefore, the structure is simple and the accuracy is high. The opening can be controlled.

Further, the cooling and heating air conditioner using the electric three-way valve according to the third aspect of the present invention is an outdoor unit 31 having a compressor 38 and an outdoor heat exchanger 35, and indoor heat exchangers 26a, 26.
a plurality of indoor units 25a and 25b having b, and cooling or heating all the rooms, or performing a cooling operation of a predetermined room and a heating operation of the other room, the above-mentioned outdoor The pipe 36 having the first electric expansion valve 32 interposed therein is branched at one end of the heat exchanger 35, and the branch pipes 37a and 37b are connected to the second electric expansion valve 33a.
33b is connected to one end sides of the indoor heat exchangers 26a and 26b, respectively, and the outdoor heat exchanger 35 and the other end sides of the indoor heat exchangers 26a and 26b are connected to the electric three-way valve A _{1 according to} claim ₁ , The second passages A ₂ and A ₃ are connected to each other, the discharge pipe 40 of the compressor 38 is connected to the first passage 2 of the first electric three-way valve A ₁ on the outdoor heat exchanger 35 side, and the discharge pipe is Four
0 is branched and connected to the first passages 2 of the second and third electric three-way valves A ₂ and A ₃ on the indoor heat exchangers 26a and 26b side, respectively, and the suction pipe 41 on the suction side of the compressor 38 is connected to the outdoor heat exchanger. Exchanger 3
While being connected to the third passage 4 of the electric five-way valve A ₁ on the 5 side,
The suction pipe 41 is branched to branch the indoor heat exchangers 26a and 26b.
It is characterized in that they are respectively connected to the third passages 4 of the second and third electric three-way valves A ₂ and A ₃ on the side.

According to the air conditioner for cooling / heating using the electric three-way valve of the third aspect, the first to third electric three-way valves A ₁ to 3 are provided on the outdoor heat exchanger 35 and the indoor heat exchangers 26a and 26b, respectively. Since A ₃ is used, each electric three-way valve A ₁ can be used even when the refrigerant circuit is used for heating all rooms or for cooling all rooms, or when a predetermined room is cooled and the remaining rooms are simultaneously operated for heating. it is only to open and close the respective valve seat to a _3.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Specific embodiments of an electric three-way valve of the present invention and a cooling / heating air conditioner using the electric three-way valve will be described in detail with reference to the drawings.
FIG. 1 shows a sectional view for explaining the operation of the electric three-way valve A. Reference numeral 1 denotes a cylindrical main body casing, and a lower portion of the main body casing 1 is used as a first passage 2. This first passage 2
A second passage 3 which is connected to the side of the main body casing 1 is formed above the main casing 1, and a third passage 4 which is connected to the side of the main casing 1 is formed above the main casing 1. Has been formed. The first passage 2, the second passage 3, and the third passage 4 are in communication with each other in the main body casing 1 by a passage 5 extending in the axial direction. A first valve seat 6 is formed between the first passage 2 and the second passage 3, and a second valve seat 6 is formed inside the third passage 4, that is, at a position between the second passage 3 and the third passage 4. A valve seat 7 is formed. A cylindrical valve body 8 is provided in the flow path 5 so as to be movable along the axial direction of the main body casing 1. The valve element 8 penetrates the inside of the second valve seat 7 and extends downward, and the valve portion 8a at the lower end thereof abuts against and separates from the first valve seat 6 so that the flow path 5 is formed. To open and close. A substantially cylindrical check valve 9 is provided in the flow path 5 on the second passage 3 side of the second valve seat 7. The check valve 9 slides on the valve body 8. The check valve 9 is freely inserted and inserted, and the check valve 9 contacts and separates from the second valve seat 8 to open and close the flow path 5.

Next, the structure of the electric drive mechanism 13 for driving and controlling the valve body 8 and the check valve 9 movably arranged in the main body casing 1 along the axial direction will be described. The electric drive mechanism 13 is arranged such that the lower surface of the case 14 is fixed to the upper surface of the main body casing 1, and the coil 15 is arranged on the outer peripheral portion of the case 14. A guide portion 16 having a hollow inside is disposed inside the case 14, and a magnet 17 is attached to the outer peripheral surface of the guide portion 16. From the center of the lower surface of the guide portion 16 to the cylindrical shaft portion 1
8 is integrally provided vertically, and a screw portion 19 is screwed on the outer peripheral surface of the shaft portion 18 over substantially the entire length. Also,
A screw hole 10 that is screwed into the screw portion 19 of the shaft portion 18 is threaded on the upper portion of the main body casing 1. The valve body 8 is axially, that is, vertically movable, supported by the guide portion 16 while penetrating the shaft portion 18, and a small-diameter shaft 11 is integrally provided on the upper surface of the valve body 8. A flat plate-like fixing member 12 is integrally formed on the upper end of the shaft 11 so as to prevent the shaft from coming off. And the shaft 1 located in the case 14
1, a coil-shaped spreading spring 20 is interposed. The upper end surface of the spring 20 makes elastic contact with the ceiling surface of the case 14, and the lower end surface of the spring 20 presses the upper end surface of the valve body 8 downward. ing.

Next, the operation of the electric three-way valve A will be described with reference to FIG. Here, the high pressure (H
P) acts, an intermediate pressure (MP) lower than the pressure of the first passage 2 acts on the second passage 3, and a low pressure (LP) lower than the second passage 3 acts on the third passage 4. It is supposed to work. If the state of FIG. 1A is assumed to be the initial state, the valve body 8 is at the uppermost position in the state of FIG. 1A, and the valve portion 8a of the valve body 8 is farthest from the first valve seat 6 and the first valve Seat 6
The maximum opening is at. Therefore, the fluid flows from the first passage 2 to the second passage 3 via the first valve seat 6 and the passage 5. At this time, the check valve 9 is biased upward by the high-pressure fluid, so that the check valve 9 closes the second valve seat 7, and the fluid is blocked by the check valve and does not flow to the third passage 4. .

When an electric current is applied to the coil 15 in the state shown in FIG. 1A, the guide portion 16 is produced by Fleming's left-hand rule.
A rotating force is generated in the guide part 16 together with the magnet 17.
Will rotate. When the guide portion 16 rotates, the screw portion 19 of the shaft portion 18 of the guide portion 16 and the screw hole 10 of the main body casing 1 are screwed together. 16 descends. At this time, when the guide portion 16 descends, the lower end of the spring 20 biases the upper surface of the valve body 8, so that the spring 20 causes the valve body 8 to descend as the guide portion 16 descends. The valve body 8 is driven downward from the state shown in FIG. 1A to the state shown in FIG. 1B, that is, until the valve portion 8a completely closes the first valve seat 6 due to the lowering of the valve body 8. Here, since the guide portion 16 and the valve body 8 are gradually lowered (moved) by the rotation of the guide portion 16, the opening degree control of the first valve seat 6 by the valve body 8 can be accurately performed. In the state of FIG. 1B, the lower end surface of the shaft portion 18 of the guide portion 16 and the upper end surface of the check valve 9 are in non-contact with each other, and the check valve 9 is the guide portion 1.
It is not pressed downward by the shaft portion 18 of 6 and is urged upward by the pressure of the fluid in the flow path 5, and therefore the second valve seat is completely closed by the check valve 9. ing. That is, the state of FIG. 1B is the same as the first valve seat 6 and the second valve seat 6.
The valve seat 7 is in a closed state, the flow of fluid is blocked in each of the passages 2 to 4, and the electric three-way valve A is in a closed state.

When the guide portion 16 is further rotated in the state of FIG. 1 (b), only the guide portion 16 is lowered by the rotation this time. That is, even if the valve body 8 is pressed downward by the elastic force of the spring 20, the valve body 8 is prevented from moving downward by the first valve seat 6, and the spring 20 only contracts. Does not descend. On the other hand, the lowering of the guide portion 16 causes the shaft portion 1 of the guide portion 16 to move.
Since the lower end surface of 8 presses against the upper end surface of the check valve 9, the check valve 9 gradually descends while sliding on the outer surface of the valve body 8 due to the lowering of the guide portion 16. The amount of opening of the second valve seat 7 increases as the check valve 9 descends, and the opening of the second valve seat 7 can be controlled by the operation of the check valve 9 due to the lowering of the guide portion 16. By controlling the opening of the check valve 9, the second passage 3
From the above, the fluid flows to the third passage 4 via the flow path 5 and the second valve seat 7. The state in which the guide portion 16 is most lowered is the state shown in FIG.

Next, when performing the reverse operation from the state of FIG. 1 (c) to (b) and (a),
By applying a voltage so that the direction of the current flowing through the coil 15 is reversed from the state of (c), the guide portion 16 is rotated in the opposite direction to the above. As the guide portion 16 rises from the state of FIG. 1C, the check valve 9 rises while sliding upward on the valve body 8 due to the pressure of the fluid flowing in the flow path 5. As the check valve 9 rises, the outer surface of the base portion having the larger diameter of the check valve 9 comes into contact with the second valve seat 7 and the second
The valve seat 7 is closed. This state is the state shown in FIG. When the guide portion 16 further rises, the guide portion 1
As the valve 6 is lifted, the valve 8 is lifted in such a manner that the valve 8 can be pulled up by the guide portion 16. As the valve body 8 rises, the valve portion 8a of the valve body 8 moves away from the first valve seat 6, so that the first valve seat 6 is controlled in the direction in which the opening degree increases.

As described above, the opening control of the first valve seat 6 by the valve body 8 and the opening control of the second valve seat 7 by the check valve 9 can be performed both in the closing direction and the opening direction. Therefore, in addition to the flow path switching function, there is an advantage that it has a flow rate adjusting function and does not generate a large switching noise when switching the opening and closing of the flow path 5. Further, since the electric three-way valve A has a simple structure, it can be formed at low cost and can be downsized. Therefore, when the electric three-way valve A is applied to the refrigerant circuit of the air conditioner, the refrigerant adjustment can be linearly controlled, and the space can be further saved.

FIG. 2 shows an embodiment in which the above electric three-way valve A is applied to a refrigerant circuit of an air conditioner. In this embodiment, the indoor units 25a and 25b have two chambers, but the invention can be applied to two or more chambers. For convenience of explanation, the case of two chambers will be described. Indoor units 25a, 25b
The indoor heat exchangers 26a and 26b and the indoor fans 27a and 27b are provided therein, respectively. Further, a temperature sensor 28 for detecting the temperature of the indoor heat exchangers 26a, 26b.
a and 28b are provided. All other members to be described later are provided on the outdoor unit 31 side, and the outdoor unit 31 and the plurality of indoor units 25a and 25b are two pipes.

A pipe 36 having an electrically driven expansion valve 32 is connected to one end of an outdoor heat exchanger 35 provided with a fan 34 of the outdoor unit 31, and this pipe 36 is a branch pipe 37.
It is branched and connected to a and 37b. This branch pipe 37a, 3
7b is connected to one end of the indoor heat exchangers 26a, 26b of the indoor units 25a, 25b via the electrically driven expansion valves 33a, 33b. The other end of the outdoor heat exchanger 35 is connected to the second passage 3 of the first electric three-way valve A ₁ and the electric three-way valve A ₁
A discharge pipe 40 from the compressor 38 is connected to the first passage 2. The third passage 4 of the first electric three-way valve A ₁ is connected to the accumulator 39 via the suction pipe 41. Further, the indoor heat exchanger 26 of the indoor units 25a and 25b
The other ends of a and 26b are connected to the second passages 3 of the second and third electric three-way valves A ₂ and A ₃ via branch pipes 42a and 42b, respectively. Further, the first passage 2 of each electric three-way valve A ₂ , A ₃ is connected to the discharge pipe 40, and the third passage 4 is connected to the suction pipe 41. Incidentally, 43 is a temperature sensor for detecting the temperature of the discharge pipe 40, and 44 is a temperature sensor called an intermediate pressure thermistor.

Next, the operation of cooling and heating operation by the refrigerant circuit shown in FIG. 2 will be described. First, in the case of cooling operation, the flow of the fluid (refrigerant) of the first electric three-way valve A ₁ on the outdoor heat exchanger 35 side is switched from the first passage 2 to the second passage 3 as indicated by the solid arrow. The indoor heat exchanger 26a,
The second and third electric three-way valves A ₂ and A ₃ on the 26b side are switched and controlled so as to flow from the second passage 3 to the third passage 4 as indicated by the solid arrow. Also, the electric expansion valve 32 is fully opened,
The electric expansion valves 33a and 33b are configured to perform target discharge pipe temperature control and gas pipe isothermal control. The refrigerant discharged from the compressor 38 is discharged from the discharge pipe 40 and the first electric three-way valve A ₁
From the first passage 2 to the second passage 3 and the outdoor heat exchanger 35 in order to condense and liquefy, and then to the branch pipe 37 via the pipe 36.
a, 37b, the electric expansion valves 33a, 33b reduce the pressure, and the indoor heat exchangers 26a, 26b evaporate and vaporize the cold air. And the indoor heat exchangers 26a and 26b
The refrigerant flowing out of the branch pipes 42a, 42b, the second and third electric three-way valves A ₂ , A ₃ from the second passage 3 to the third passage 4, the suction pipe 4
1, and is sequentially sucked into the compressor 38 through the accumulator 39. In this way, all the chambers (two chambers in this case) are cooled at the same time in each of the indoor heat exchangers 26a and 26b acting as the evaporator.

On the contrary, when heating all the rooms at the same time, the electric three-way valves A _{1 to} A ₃ are switched and controlled as follows. First, in the first electric three-way valve A ₁ , switching control is performed so that the refrigerant flows from the second passage 3 to the third passage 4 as indicated by a dashed arrow, and the second and third electric three-way valves A ₂ and A ₃ are indicated by broken lines. Switching control is performed so that the refrigerant flows from the first passage 2 to the second passage 3 as indicated by the arrow. In addition, the electric expansion valve 3
2 is fully opened, and the electric expansion valves 33a and 33b are configured to perform target discharge pipe temperature control, SC control, and the like. The refrigerant discharged from the compressor 38 is the discharge pipe 40 and the discharge pipe 4
0 to the side of the branch pipes 42a, 42b, and the second and third
The electric three-way valves A ₂ and A ₃ flow from the first passage 2 to the second passage 3 and the indoor heat exchangers 26 a and 26 b, and the refrigerant is condensed and liquefied in the indoor heat exchangers 26 a and 26 b, respectively, and then the electric expansion valve. Decompressed by 33a, 33b, branch pipes 37a, 37b
Via the electric expansion valve 32 and evaporatively vaporized in the outdoor heat exchanger 35, and then through the second passage 3 to the third passage 4 and the accumulator 39 of the first electric three-way valve A ₁ to the compressor. Inhaled at 38. In this way, all the indoor heat exchangers 26a and 26b acting as condensers simultaneously heat all the rooms.

Next, a case where one room is cooled and the remaining one room is heated, for example, when the first indoor unit 25a is cooled and the second indoor unit 25b is heated will be described. At this time, the first electric three-way valve A ₁ is connected to the first passage 2 indicated by the solid arrow.
Switching control is performed so that the refrigerant flows from the second passage 3 to the second passage 3.
The electric three-way valve A ₂ is switch-controlled so that the refrigerant flows from the second passage 3 to the third passage 4 as indicated by the solid arrow, and the third electric three-way valve A ₃ is changed from the first passage 2 as indicated by the dashed arrow. Second
Switching control is performed so that the refrigerant flows through the passage 3. Then, the electric expansion valve 32 is set to a small opening degree to adjust the excess refrigerant.
The electric expansion valves 33a and 33b perform target discharge pipe temperature control and SC control while controlling the temperature detected by the temperature sensor 44 to be about 5 ° C. lower than the outside air temperature. Further, the electric expansion valve 32 and the first electric three-way valve A ₁ are configured to control the opening degree by determining the amount of circulating refrigerant by the temperature sensors 28a and 28b. A part of the refrigerant discharged from the compressor 38 flows into the outdoor heat exchanger 35 through the discharge pipe 40, the first passage 2 of the first electric three-way valve A ₁ and the second passage 3, and at the same time, the refrigerant from the compressor 38 is discharged. The rest of the discharge pipe 40, the third
From the first passage 2 of the electric three-way valve A ₃ through the second passage 3 to the second passage 3
The second indoor heat exchanger 2 flows to the indoor heat exchanger 26b.
6b and the outdoor heat exchanger 35 are condensed and liquefied.
The refrigerant condensed and liquefied in the heat exchangers 26b and 35 is decompressed by the electric expansion valves 32 and 33b, and the branch pipe 37a.
At the first indoor heat exchanger 26a through the electric expansion valve 33a. And this first indoor heat exchanger 26a
Is evaporated and vaporized, and is sucked into the compressor 38 from the second passage 3 of the second electric three-way valve A ₂ through the third passage 4, the suction pipe 41 and the accumulator 39. In this way, one room is heated by the second indoor heat exchanger 26b acting as a condenser, and the other room is cooled by the first indoor heat exchanger 26a acting as an evaporator.

Here, in the simultaneous cooling and heating operation such as cooling one room and heating the other room, the outdoor heat exchanger 35 is operated so that excess refrigerant accumulates. By the way, the outdoor heat exchanger 35 has almost the same temperature as the outside air temperature. However, when the temperature of the pipe 36 becomes higher than the outside air temperature by the temperature sensor 44 provided in the pipe 36, the pressure of the pipe 36 is changed to the outdoor heat exchanger 35.
It becomes higher, and the refrigerant flows backward from the indoor heat exchangers 26a and 26b to the outdoor heat exchanger 35. Therefore, in order to prevent the refrigerant from flowing backward from the indoor heat exchangers 26a and 26b to the outdoor heat exchanger 35 and becoming insufficient, the temperature of the pipe 36 is detected by the temperature sensor 44, and the temperature detected by the temperature sensor 44 is detected. The electric expansion valves 33a and 33b are adjusted so that the temperature becomes lower than the outside air temperature by about 5 ° C. That is, when the detected temperature rises, the electric expansion valve 33a is controlled to open and the electric expansion valve 33b is controlled to close, so that the temperature of the pipe 36 decreases and the refrigerant flows back to the outdoor heat exchanger 35. Can be prevented. That is, in the simultaneous cooling / heating operation, it is necessary to secure the amount of the refrigerant circulating between the indoor heat exchangers 26a and 26b, so that the refrigerant is prevented from flowing back to the outdoor heat exchanger 35. . In addition, the temperatures DCA and DC of the indoor heat exchangers 26a and 26b, respectively.
Although B is detected by the temperature sensors 28a and 28b, respectively, the temperatures DCA and D of the indoor heat exchangers 26a and 26b are detected.
When CB becomes high, the refrigerant circulation amount becomes excessive,
The control is performed so that the refrigerant is stored in the outdoor heat exchanger 35.
In addition, the temperatures DCA and D of the indoor heat exchangers 26a and 26b, respectively.
When the CB becomes low, the circulation amount of the refrigerant tends to be insufficient, so control is performed in the direction of discharging the refrigerant from the outdoor heat exchanger 35. FIG. 3 shows how to control these. In FIG. 3, the operating frequency of the compressor 38 is also changed at the same time. That is, the temperature DC of the indoor heat exchangers 26a and 26b
When A and DCB increase, the electric expansion valve 32 is closed and the first electric three-way valve A ₁ is controlled to open. Further, the temperature DCA of the indoor heat exchangers 26a and 26b,
When DCB becomes low, the electric expansion valve 32 is opened and the first electric three-way valve A ₁ is controlled to be closed. When the temperature DCA is high and the temperature DCB is low, the operating frequency of the compressor 38 is increased, and in the opposite case, the operating frequency is decreased.

As described above, in the above-described embodiment, the electric three-way valve A is used instead of the conventional switching valve or three-way valve, so that heating or cooling of all rooms or simultaneous operation of cooling and heating of a plurality of rooms is possible. Even when it is performed, the system can be easily constructed only by opening and closing the first valve seat 6 and the second valve seat 7 of the electric three-way valve A. Further, the electric three-way valve A does not generate switching noise as in the conventional case, high quality and high efficiency can be achieved, linear control of refrigerant adjustment is possible, and further space saving can be achieved.

[0026]

According to the electrically operated three-way valve of the first aspect of the present invention, the flow rate can be adjusted in addition to the switching function, and the generation of switching noise as in the prior art can be suppressed. In addition, the product can be provided at low cost, space saving, high quality, and high efficiency.

According to the electric three-way valve of the second aspect,
It is possible to smoothly move the valve element and the check valve in the axial direction. Therefore, the fluid amount can be controlled easily and accurately.

According to the cooling / heating air conditioner using the electric three-way valve according to the third aspect, since the electric three-way valves are used on the outdoor heat exchanger side and the indoor heat exchanger side, respectively, the refrigerant circuit is heated in all rooms. Alternatively, when all the rooms are cooled, or when a predetermined room is cooled and the remaining rooms are simultaneously operated for heating, it is sufficient to open and close each valve seat of the electric three-way valve. Therefore, it becomes easy to construct such a system. Also,
The electric three-way valve does not generate switching noise as in the conventional case, high quality and high efficiency can be achieved, linear control of refrigerant adjustment is possible, and further space saving can be achieved.

[Brief description of drawings]

FIG. 1 is an operation explanatory diagram of an electric three-way valve according to an embodiment of the present invention.

FIG. 2 is a refrigerant circuit diagram using the electric three-way valve.

FIG. 3 is an operation explanatory view of the refrigerant circuit.

FIG. 4 is a refrigerant circuit diagram for a conventional cooling / heating simultaneous operation.

FIG. 5 is a refrigerant circuit diagram for another conventional cooling / heating simultaneous operation.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Main body casing 2 1st passage 3 2nd passage 4 3rd passage 5 Flow passage 6 1st valve seat 7 2nd valve seat 8 Valve body 8a Valve part 9 Check valve 10 1st screw hole 13 Electric drive mechanism 15 Coil 16 Guide portion 18 Shaft portion 20 Spring 25a, 25b Indoor unit 26a, 26b Indoor heat exchanger 31 Outdoor unit 32 First electric expansion valve 33a, 33b Second electric expansion valve 35 Outdoor heat exchanger 36 Piping 37a, 37b Branch tube 38 compressor 40 discharge pipe 41 the suction pipe A motorized three-way valve A ₁ to A ₃ electrically-driven three-way valve

Claims (3)

[Claims] 1. A flow passage (5) extending in the axial direction is formed in a main body casing (1), one end side of the flow passage (5) is a first passage (2), and the other end side is a third. The passage (4) is connected to the second passage (3) at an intermediate portion thereof, and in the passage (5), between the first passage (2) and the second passage (3). Connect the first valve seat (6) to the second passage (3)
A second valve seat (7) is provided between the second valve seat (7) and the third passage (4), and penetrates the second valve seat (7) in the flow path (5) along its axial direction. A valve body (8) extending toward the first valve seat (6) side, and the opening degree is controlled by approaching or separating from the first valve seat (6) on the tip side of the valve body (8). A valve portion (8a) for the second valve is provided on the valve body (8).
A check valve (9) is slidably inserted into a position closer to the tip side than the valve seat (7), and the check valve (9) is pushed by the fluid pressure acting in the flow path (5). Is configured to close the second valve seat (7), and further the valve body (8) and the check valve (9).
An electric drive mechanism (13) for driving the valve is provided, and by this electric drive mechanism (13), the check valve (9) opens the second valve seat (7) by the fluid pressure in the flow path (5). The first state in which the opening degree is controlled in the first valve seat (6) by the axial movement of the valve body (8) while being closed, the flow path (5)
The second state in which the check valve (9) closes the second valve seat (7) by the fluid pressure inside and the first valve seat (6) is closed by the valve body (8), the flow path ( 5) By moving the check valve (9) against the fluid pressure in the second valve seat (7)
The electric three-way valve is characterized in that it is configured to form a third state in which the first valve seat (6) is closed by the valve body (8) while controlling the opening degree in 1. 2. The electric drive mechanism (13) is provided with a shaft portion (18) on a guide portion (16) which is rotationally driven by an electric current flowing through a coil (15), and the shaft portion (1).
8) is screwed into a screw hole (10) provided in the main body casing (1) to convert the rotation of the guide portion (16) into a linear reciprocating motion. Is introduced into the flow channel (5) slidably through the shaft portion (18), and the valve body (8) is interlockable with the guide portion (16) and The guide portion (16) moves the valve body (8) in the direction of closing the first valve seat (6),
As a result, after the valve portion (8a) of the valve body (8) contacts the first valve seat (6), the guide member (16) can be further moved in the same direction so that the guide member (16) can move in the same direction. The guide member (16) is moved in the same direction so that the tip of the shaft portion (18) pushes the check valve (9) in the valve opening direction. The electric three-way valve according to claim 1, wherein 3. A compressor (38) and an outdoor heat exchanger (35)
An outdoor unit (31) having an indoor heat exchanger (2)
6a) and (26b) a plurality of indoor units (25
a) (25b), wherein all the rooms are cooled or heated, or a predetermined room is cooled and the other rooms are heated, the outdoor heat exchanger (35) A pipe (36) having a first electric expansion valve (32) interposed at one end side of each of the branch pipes (37a)
(37b) is connected to one end sides of the indoor heat exchangers (26a) (26b) via the second electric expansion valves (33a) (33b), and the outdoor heat exchanger (35) and each indoor heat exchanger are connected. The second passages (3) of the electric three-way valves (A ₁ ) (A ₂ ) (A ₃ ) according to claim 1 are connected to the other ends of the (26a) and (26b), respectively, and are connected to the compressor (38). The discharge pipe (40) is the first of the first electric three-way valve (A ₁ ) on the outdoor heat exchanger (35) side.
The first of the second and third electric three-way valves (A ₂ ) (A ₃ ) on the indoor heat exchanger (26a) (26b) side is connected to the passage (2) and the discharge pipe (40) is branched. The suction pipe (4) on the suction side of the compressor (38) is connected to the passage (2).
1) is connected to the third passage (4) of the first electric three-way valve (A ₁ ) on the side of the outdoor heat exchanger (35), and the suction pipe (41) is branched so that the indoor heat exchanger (26 a). (26
A cooling / heating air conditioner using an electric three-way valve, which is connected to the third passages (4) of the second and third electric three-way valves (A ₂ ) (A ₃ ) on the b) side, respectively.